class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;

    TreeNode() {
    }

    TreeNode(int val) {
        this.val = val;
    }

    TreeNode(int val, TreeNode left, TreeNode right) {
        this.val = val;
        this.left = left;
        this.right = right;
    }
}

public class TestB {

}

class Solution1 {
    public boolean isSameTree(TreeNode p, TreeNode q) {
        if (p == null && q != null || p != null && q == null ) return false;
        if (p == q) return true;
        if (p.val != q.val) return false;
        return isSameTree(p.left,q.left) && isSameTree(p.right,q.right);
    }
}

class Solution2 {
    public boolean isSubtree(TreeNode root, TreeNode subRoot) {
        Solution1 solution1 = new Solution1();
        if (subRoot == null) {
            return true;
        }
        if (root == null) {
            return false;
        }
        if (solution1.isSameTree(root,subRoot)) {
            return true;
        }
        return isSubtree(root.left,subRoot) && isSubtree(root.right,subRoot);
    }
}

class Solution3 {
    public boolean isBalanced(TreeNode root) {
        
    }
}